Passenger cars basically have the problem of being relatively poorly protected against a collision from the side, since only a slight collapsible zone is available here. Especially vehicles, in which the B column is disposed within the vertical extent of a side wall of the car body forming the occupants' space below a window breast, have the peculiarity that the B column ends below the window breast and that therefore neither a transverse beam, spanning the occupants' space in the form of a roll bar in the case of a convertible nor a lashing to the roof of the B columns in the case of a closed vehicle, is present. As a result, the stability of the side walls is relatively slight, so that, in the case of a side collision, considerable intrusion can occur and endanger the occupants.